Richard Gibbens. Why Do We Fatigue. A Dynamic Model of Fatigue. 2007. Power Running WebSite
http://www.powerrunning.com/Exercise%20Physiology/Why%20do%20we%20fatigue%20A%20Dynamic%20Model%20of%20Fatigue.htm
i saw this thread yesterady but didnt get a chance to read it till today.very interesting, his work parallels my beliefs on fatigue but not just that it occurs as some kind of mental process but that there is an actual neurological process which does not have to occur in the brain which limits motor output ability. interneurons can and do provide inhibitory signals to motor neurons therby causing fatigue. this interneurons also serve other purposes during maximal balistic activities in the form of effecient muscular coordination.
Control mechanism may not be in brain at all… it may have peripheral aspects as well, as you have pointed out. For example slowing down of neural signal transition on alpha-MN… Peripheral fatigue may be a control mechanism too…
The most interesting point is that ‘root of fatigue’ (aka limiting factor) (on whinch CG reacts and creates fatigue) changes as athlete adapt.
Limiting factors for 5k are not the same for fat lady, kid, old guy, medicre runner and elite runner. Indentifying and adressing them is one of the aims of training system.
We fatigue because of oxidative stress. People will know exactly what I’m talking about if they’ve tinkered with antioxidant supplements. When you’re on them you can DEFINITELY tell you don’t fatigue as easily.
i wont deny that oxidation can contribute to fatigue but to state that its is the cause of fatigue is a blanket statement and the link posted presents strong evidence that oxidative factors are not the cause of fatigue but possible a contributing factor.
The “CNS fatigue” I describe has two sides to it:
First is the inability to repeat current performance levels within the expected (or planned) time frame.
Second is the inability to continue to improve on immediate past performance in an expected fashion, adjusted for expected adaptation stresses.
I am not referring to the conditions that create the inability to continue an action in progress.
i see your point charlie. but if an individual had a better understanding of the condtions which produce fatigue they can increase ability to repeat current performance levels within the expected time frame and increase the ability to continue to improve on immediate past performance in an expected fashion. both are desired, yes?
Not sure I follow. An existing Special Endurance level/performance includes the manner in which it is executed.
Wouldn’t the ability to resist fatigue be included in performance improvement?
i think its better to say to “recover from fatigue” as opposed to “resist fatigue”. the ability to resist fatigue would indicate some sort of supercompensation. some sort of stress must occur for supercompensation to occur. the greater the stress (within limits) the greater the resulting supercompensation. a stress which does no disturb the bodies homeostatic state will not produce and adaptation. so we dont necessarily want to resist fatigue to train more often we want to be able to recover from said fatigue more rapidly. ofcourse the external stimuli must increase with adaptation, to former, less intense stimuli. i geuss its all based on your definition of the terms.
a stress which does no disturb the bodies homeostatic state
what would a stress of this type be?
I agree it is mostly semantics, but i still think there are some underlying issues of philosophy even given semantic issues, i’m really interested to see how this pans out.
This definition of CNS fatigue-be it truly CNS what it refers to,or not -goes well beyond understanding “the conditions that create the inability to continue an action in progress”,as if you are truly able to fully manage the two limiting factors described above,you’ll never need to understand more.
The need for all the understanding comes from not being able to keep the whole process in its dynamic simplicity,as failure to do so in one area or the other,will abruptly throw us back into the complex reality of human adaptation,requiring correspondingly complex understanding.
a stress that is too weak such as a person trying to improve their squat using 100 lbs when they are already a 600 lb squater. unless they squat for max velocity the stimulus will be to weak to disturb homeostatic balance.
In scientifical papers ‘CNS fatigue’ is the decrease in neural output on muscles when muscles show increase in power output when additionally stimulated artifically with EMS. In other words: muscles are able to provide the additional power, but CNS (brain or some lower neural components: spine) won’t stimulate.
I guess that the term ‘CNS Fatigue’ Charlie implys/implyed till now is rather a from of High Intensity Strain/Overreaching/Overtraining as an delayed phenomena, both as cumulative effect and as training effect, than is a ‘current’ decrease in power output due decrease in CNS output.
During marathon, marathoners may express CNS fatigue, or decrease in CNS output due (a) lack of glycogen, (b) dehydration © build up of H+, (d) impairment of bodyli systems (fatigue of heart, diaphragm…), (e) over-heating, (f) muscle injury…
Thus the definition of the scientifical terms and CF’s terms are not in disagreement, but rather pointing to other things.
In this case, I meant resist because I was referring to keeping going during a single SE run
Yes. My definition is different.
Would “maintain a sustained level of output” be better then?